Fuel cell power generation system

Abstract

The present invention discloses a fuel cell power generation system, which comprises: a gas distribution box including a plurality of gas distribution cavities separated from each other for accommodating gases; and a plurality of stack towers (200) arranged around the periphery of the gas distribution box and including an upper stack (210), a gas distribution plate (220) and a lower stack (230) stacked vertically. The gas distribution box is combined with the surrounding plurality of stack towers, and anode fuel gas, cathode intake gas, anode exhaust gas and cathode exhaust gas are concentrated in the gas distribution box. The anode fuel gas and the cathode intake gas are transmitted and radiated from the center to the outside and gradually diffuse into the upper stack and the lower stack. The structural design of the gas distribution box can reduce pipelines, make the structure compact, play a heat exchange role at the same time, ensure the uniformity of gas distribution between a plurality of upper stacks and a plurality of lower stacks, enable uniform gas distribution for each stack, reduce stack damage, improve fuel utilization rate, and ensure the stable operation of the power generation system.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cell power generation, and particularly relates to a fuel cell power generation system. Background Art

[0002] A solid oxide fuel cell is an electrochemical power generation device that converts the chemical energy of a fuel gas reaction into electrical energy. Its advantages of high efficiency, cleanliness, and the ability to be applied nearby make it a very promising new energy power generation device. The integration of a high-power fuel cell system requires connecting multiple solid oxide fuel cell stacks in series or parallel to form a large battery pack, and then transporting reaction gases to each stack through pipelines for chemical reactions to generate electricity. The uniformity of gas distribution affects the consistency of the stacks. If the gas supplied to a certain stack is insufficient, it will cause a decrease in the power generation of the stack, and long-term operation will damage the stack; if the gas flow rate supplied to the stack is too large, it will result in low fuel utilization rate of the system and high costs. Therefore, the uniform distribution of gas is one of the key concerns in the fuel cell integration system. Summary of the Invention

[0003] Aiming at the above-mentioned defects or deficiencies of the prior art, the present invention provides a fuel cell power generation system. In this fuel cell power generation system, gas is uniformly transmitted to each stack tower, enabling uniform gas distribution in each stack, reducing stack damage, improving fuel utilization rate, and ensuring the stable operation of the power generation system.

[0004] To achieve the above object, according to the fuel cell power generation system of the present invention, the fuel cell power generation system includes:

[0005] A gas distribution box, including a plurality of gas distribution cavities separated from each other for accommodating gas; and

[0006] A plurality of stack towers, arranged around the periphery of the gas distribution box and including an upper stack, a gas distribution plate, and a lower stack stacked vertically;

[0007] Wherein, at least the anode fuel gas cavity, the anode tail gas cavity, the cathode intake cavity, and the cathode tail gas cavity connected to the gas distribution plate are included in the plurality of gas distribution cavities, so that the plurality of upper stacks and the plurality of lower stacks can synchronously introduce and discharge gas.

[0008] In some embodiments, the gas distribution box includes a plurality of gas distribution units for forming the gas distribution cavities, and the gas distribution unit includes:

[0009] A box housing, surrounding and defining the gas distribution cavity;

[0010] A plurality of gas distribution branch pipes, one end of which is arranged at intervals on the peripheral wall surface of the box housing, and the other end is connected to the gas distribution plate;

[0011] The air distribution main pipe is vertically extended and arranged on the end face of the box housing.

[0012] In some embodiments, a plurality of the box housings are coaxially arranged and nested inside and outside.

[0013] In some embodiments, among a plurality of the box housings, at least a first box housing, a second box housing, a third box housing, and a fourth box housing are arranged from outside to inside. The inner wall of the fourth box housing surrounds and defines the anode gas chamber. The inner wall of the third box housing and the outer wall of the fourth box housing jointly surround and define the anode tail gas chamber. The inner wall of the second box housing and the outer wall of the third box housing jointly surround and define the cathode intake gas chamber. The inner wall of the first box housing and the outer wall of the second box housing jointly surround and define the cathode tail gas chamber.

[0014] In some embodiments, within the same air distribution unit, the lengths of a plurality of the air distribution branch pipes are the same and are arranged in the same plane; and / or, the air distribution branch pipes include proximal ends of the branch pipes connected to the box housing, and the distances between adjacent proximal ends of the branch pipes are the same.

[0015] In some embodiments, the air distribution unit further includes:

[0016] A plurality of flow guiding ribs, which are vertically extended and arranged inside the box housing for dispersing the gas in the air distribution gas chamber; and

[0017] A flow guiding cover, which is located in the air distribution main pipe and covers the air distribution main pipe;

[0018] Wherein, a plurality of flow guiding holes for communicating the air distribution main pipe and the air distribution gas chamber are formed on the flow guiding cover at circumferentially spaced intervals.

[0019] In some embodiments, the air distribution box is an insulating and high-temperature resistant structural member.

[0020] In some embodiments, the box housing and the air distribution plate are respectively welded and fixed to the air distribution branch pipe.

[0021] In some embodiments, both the upper fuel cell stack and the lower fuel cell stack are single fuel cell stacks and include a plurality of battery sheets stacked vertically, an upper protection plate located at the top of the battery sheets, and a lower protection plate located at the bottom of the battery sheets. Power-taking lugs protrude from both the upper protection plate and the lower protection plate.

[0022] In some embodiments, the fuel cell power generation system further includes a conductive power-taking connection assembly, and the power-taking connection assembly includes:

[0023] A power-taking connection plate, which is formed with a lug accommodation groove for accommodating the power-taking lugs; and

[0024] A fixing member, the power-taking ear is inserted into the ear accommodating groove and electrically connected to the power-taking connecting plate, and the fixing member penetrates through the power-taking connecting plate and the power-taking ear;

[0025] Wherein, in the same fuel cell stack tower, the power-taking connecting plate at the top of the lower fuel cell stack is connected to the power-taking connecting plate at the bottom of the upper fuel cell stack through an inter-stack connecting plate, so that the upper fuel cell stack and the lower fuel cell stack are connected in series.

[0026] In some embodiments, the fuel cell power generation system further includes a power-taking support rod for outputting the electric energy of the fuel cell stack tower. The power-taking support rod includes an upper power-taking support rod and a lower power-taking support rod. The upper power-taking support rod extends from the power-taking connecting plate located at the top of the upper fuel cell stack, and the lower power-taking support rod extends from the power-taking connecting plate located at the bottom of the lower fuel cell stack.

[0027] In some embodiments, the inter-stack connecting plate and the power-taking connecting plate are an integral structural member.

[0028] In some embodiments, the power-taking connecting plate is a U-shaped member and includes an ear-facing surface arranged towards the power-taking ear and an ear-backing surface arranged away from the power-taking ear. The ear-facing surface surrounds and defines the ear accommodating groove. A high-temperature resistant conductive adhesive is provided between the power-taking ear and the ear-facing surface, and insulating coatings are provided on both the ear-backing surface and the inter-stack connecting plate.

[0029] In the fuel cell power generation system of the present invention, a combination method of a gas distribution box and a plurality of surrounding fuel cell stack towers is adopted. Among them, the anode fuel gas, cathode intake air, anode tail gas, and cathode tail gas are all concentrated in the gas distribution box and arranged at the center of the plurality of fuel cell stack towers. The anode fuel gas and cathode intake air are transmitted and radiated from the center to the outside, and gradually diffuse into the upper fuel cell stack and the lower fuel cell stack. The uniformity of gas distribution between the plurality of upper fuel cell stacks and the plurality of lower fuel cell stacks is ensured, so that each fuel cell stack is evenly distributed with gas, reducing fuel cell damage, improving fuel utilization rate, and ensuring the stable operation of the power generation system. The pipeline is reduced, making the structure compact. At the same time, the high-temperature tail gas and the low-temperature reaction gas can exchange heat through the gas box housing, reducing the temperature of the high-temperature tail gas, increasing the temperature of the reaction gas, and increasing the thermal utilization rate of the integrated structure.

[0030] Other features and advantages of the present invention will be described in detail in the subsequent specific implementation part. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the following specific implementation, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0032] Figure 1Schematic three-dimensional structure diagram of a fuel cell power generation system according to a specific embodiment of the present invention;

[0033] Figure 2 It is Figure 1 Partial structure diagram, showing the air distribution box;

[0034] Figure 3 It is Figure 2 Partial structure diagram, showing the first box housing;

[0035] Figure 4 It is Figure 2 Partial structure diagram, showing the second box housing;

[0036] Figure 5 It is Figure 2 Partial structure diagram, showing the third box housing;

[0037] Figure 6 It is Figure 2 Partial structure diagram, showing the fourth box housing;

[0038] Figure 7 It is Figure 6 Partial internal structure diagram, showing the flow guiding ribs, flow guiding covers and flow guiding holes;

[0039] Figure 8 It is Figure 6 Internal structure diagram from different perspectives, showing the flow guiding ribs, flow guiding covers and flow guiding holes;

[0040] Figure 9 It is Figure 1 Partial structure diagram, showing the stack tower of the fuel cell stack;

[0041] Figure 10 It is Figure 9 Structure diagram from different perspectives, showing the stack tower of the fuel cell stack;

[0042] Figure 11 It is Figure 9 Partial structure diagram, showing a structure of the power taking connection component;

[0043] Figure 12 It is Figure 11 Structure diagram from different perspectives, showing a structure of the power taking connection component;

[0044] Figure 13 It is Figure 9 Partial structure diagram, showing another structure of the power taking connection component;

[0045] Figure 14 It is Figure 13 Structure diagram from different perspectives, showing another structure of the power taking connection component;

[0046] Figure 15 For Figure 9 the partial structure diagrams from different perspectives, showing a single cell stack.

[0047] Description of the reference numerals:

[0048] 100 Gas distribution unit

[0049] 110 Box housing

[0050] 1110 First box housing 1120 Second box housing

[0051] 1130 Third box housing 1140 Fourth box housing

[0052] 120 Gas distribution branch pipe

[0053] 1210 Near end of the branch pipe 1220 Far end of the branch pipe

[0054] 1230 Anode gas branch pipe 1240 Anode tail gas branch pipe

[0055] 1250 Cathode intake branch pipe 1260 Cathode tail gas branch pipe

[0056] 130 Gas distribution main pipe

[0057] 1310 Anode gas main pipe 1320 Anode tail gas main pipe

[0058] 1330 Cathode intake main pipe 1340 Cathode tail gas main pipe

[0059] 200 Cell stack tower

[0060] 210 Upper cell stack 220 Gas distribution plate

[0061] 230 Lower cell stack

[0062] 300 Power extraction connection component

[0063] 310 Power extraction connection plate 320 Fixing part

[0064] 330 Inter-stack connection plate

[0065] 3110 Ear facing surface 3120 Ear back surface

[0066] 1 Battery cell 2 Upper protection plate

[0067] 3 Lower protection plate 4 Power extraction ear

[0068] 5 Ear receiving groove 6 Power extraction upper rod

[0069] 7 Power extraction lower rod 8 Flow guiding rib

[0070] 9 Fairing 10 Fairing hole Detailed implementation manners

[0071] The following will describe in detail the specific implementation manners of the present invention with reference to the accompanying drawings. It should be understood that the specific implementation manners described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0072] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0073] In the present invention, unless otherwise stated, the orientation words such as "upper, lower, top, bottom" are usually in the direction shown in the accompanying drawings or in the vertical, perpendicular or gravitational direction for describing the relative position relationship of each component.

[0074] The following will describe the present invention in detail with reference to the accompanying drawings and in combination with embodiments.

[0075] Fuel cell integration technology can integrate multiple fuel cell power generation modules, convert the chemical energy of fossil fuels into electrical energy through electrochemical reactions, and achieve clean and efficient utilization of fossil energy. A fuel cell power generation system is disclosed in the present invention, and reaction gases are transported to each stack through pipelines for chemical reactions to generate electricity. The power generation power of the stack is closely related to the transmission of reaction gases. Insufficient or excessive transmission of reaction gases will affect the performance of the stack and even damage the stack. Therefore, how to maintain the uniform and stable transmission of reaction gases is a problem worthy of research.

[0076] Therefore, in the fuel cell power generation system, its gas distribution structure is designed. The present invention provides a fuel cell power generation system with a new structure. Refer to Figures 1 to 15 the specific implementation manners, the fuel cell power generation system, the fuel cell power generation system includes: a gas distribution box and a plurality of stack towers 200;

[0077] Specifically, the gas distribution box includes a plurality of gas distribution cavities separated from each other for accommodating gases. The gases in the fuel cell power generation system usually include anode fuel gas, cathode intake gas, anode tail gas and cathode tail gas, and the cathode intake gas is generally air. The gas distribution box can accommodate or buffer a certain amount of gas, so as to facilitate the stable and uniform supply of gas; and

[0078] A plurality of stack towers 200 are arranged around the periphery of the gas distribution box and include an upper stack 210, a gas distribution plate 220 and a lower stack 230 stacked vertically. The plurality of stack towers 200 are arranged around the periphery of the gas distribution box, so that the structure is compact and the integration degree of the fuel cell power generation system is improved;

[0079] Among them, at least the anode gas chamber, the anode tail gas chamber, the cathode intake gas chamber, and the cathode tail gas chamber connected to the gas distribution plate 220 are included in the multiple gas distribution chambers, so that the multiple upper fuel cells 210 and the multiple lower fuel cells 230 can synchronously introduce and discharge gas, as Figure 1 shown. The anode fuel gas, the cathode intake gas, the anode tail gas, and the cathode tail gas are all concentrated in the gas distribution box and arranged at the center of the multiple fuel cell stacks 200. The anode fuel gas and the cathode intake gas as reaction gases are transmitted from the central position along the pipeline into the multiple gas distribution plates 220. Each fuel cell stack 200 can include two fuel cells. The reaction gases entering the gas distribution plate 220 diffuse upward and downward into the upper fuel cells 210 and the lower fuel cells 230. The anode tail gas and the cathode tail gas as tail gases enter the gas distribution box from the outside to the inside and are discharged along the gas distribution box. In this way, the uniformity of gas distribution between the multiple upper fuel cells 210 and the multiple lower fuel cells 230 is ensured, so that each fuel cell is evenly distributed with gas, reducing fuel cell damage, improving fuel utilization rate, and ensuring the stable operation of the power generation system.

[0080] Optionally, the multiple gas distribution chambers in the gas distribution box can be stacked vertically, that is, the gas distribution box and the fuel cell stack 200 are arranged in parallel at intervals. Multiple partitions can be arranged at intervals from top to bottom in the gas distribution box, so that the gas distribution chambers are stacked in sequence. Among them, the extension line at the junction of the gas distribution chamber of the anode fuel gas and the gas distribution chamber of the cathode intake gas can be located on the gas distribution plate 220. In this way, the distances between the anode fuel gas and the cathode intake gas and the gas distribution plate 220 are the same, ensuring the uniform and stable supply of both. The volumes of the multiple gas distribution chambers can be the same or different, and can be adjusted according to the flow rates and flows of the respective gases, and no specific limitation is made here.

[0081] Optionally, the multiple gas distribution chambers in the gas distribution box can be nested inside and outside. In this way, all the multiple gas distribution chambers can be located at the gas distribution plate 220, so that the lengths of the pipelines between each gas distribution chamber and the gas distribution plate 220 are approximately the same, ensuring the uniform and stable transmission of gas. In particular, the centers of the multiple gas distribution chambers can coincide with each other. In this way, the distances between each gas distribution chamber and the multiple gas distribution plates 220 are the same, realizing the uniform gas distribution of the multiple fuel cell stacks 200, reducing fuel cell damage, improving fuel utilization rate, and ensuring the stable operation of the power generation system. In addition, the shape of the gas distribution box can be various, such as a cube, a hexahedron, an octahedron, or a cylinder that can ensure that the distances between each gas distribution plate 220 and the gas distribution box are all equal, and no specific limitation is made here.

[0082] Optionally, for the stack of fuel cells, the upper stack 210 and the lower stack 230 are connected in series by stacking them vertically, and a gas distribution plate 220 capable of distributing gas is placed between the upper stack 210 and the lower stack 230. An insulating gasket can be placed between the gas distribution plate 220 and the upper stack 210 and the lower stack 230. The insulating gasket can be made of high-temperature resistant mica material or vermiculite material. By passing gas through the gas distribution plate 220 to both the upper stack 210 and the lower stack 230 simultaneously, the gas distribution uniformity of the upper stack 210 and the lower stack 230 can be improved, ensuring the stable operation of each fuel cell stack.

[0083] Optionally, for the number of fuel cell stacks 200, the fuel cell stack 200 can be a single stack. In this case, only one straight pipe is needed for the gas distribution branch pipe 120 connecting the gas distribution plate 220 in the middle of the stack to the gas distribution box. However, it should be noted that the fuel cell stack 200 can also be a double stack, with one gas distribution plate 220 in each stack. At this time, the branch pipe connecting the gas distribution plate to the gas distribution box needs to be a tee branch pipe. In addition, the fuel cell stack can also be three, four or more, and the distance between adjacent two fuel cell stacks is the same. In this way, the fuel cell stacks are evenly distributed, ensuring the uniformity of gas distribution for each fuel cell stack.

[0084] Optionally, the upper stack 210 and the lower stack 230 can be single fuel cells. In this case, each gas distribution plate 220 only needs to supply gas to the two single fuel cells above and below, and the gas is evenly distributed, ensuring the stable operation of the fuel cells. However, it should be noted that the upper stack 210 and the lower stack 230 are not limited to single fuel cells. For example, the upper stack 210 and the lower stack 230 can also be distributed as two fuel cells. At this time, the internal gas delivery pipelines of the two fuel cells in direct contact with the gas distribution plate 220 can penetrate and extend into the corresponding fuel cells. In this way, the gas can be relatively evenly distributed to the upper stack 210 and the lower stack 230 through the gas distribution plate 220. The two fuel cells share one gas distribution plate, improving the gas uniformity of the upper and lower fuel cells.

[0085] To ensure the stable transmission of the gas distribution box, in one embodiment, the gas distribution box includes a plurality of gas distribution units 100 for forming a gas distribution cavity. The gas distribution unit 100 includes: a box housing 110 that surrounds and defines the gas distribution cavity; a plurality of gas distribution branch pipes 120, one end of which is arranged at intervals on the peripheral wall surface of the box housing 110, and the other end is connected to the gas distribution plate 220; and a gas distribution main pipe 130 that extends vertically on the end surface of the box housing 110, as Figures 2 to 6As shown in the figure. Among them, the box housing 110 can be a cube and includes a box peripheral wall arranged around and box end walls covering the top and bottom ends of the box peripheral wall. A plurality of gas distribution branch pipes 120 can be respectively located at the centers of the respective faces of the box peripheral wall, and the gas distribution main pipe 130 can be located on at least one of the two box end walls. For the anode gas and the cathode intake gas as reaction gases, the reaction gases enter the box housing 110 from the gas distribution main pipe 130 and enter the gas distribution plate 220 connected thereto along the gas distribution branch pipes 120 distributed on the box housing 110. In this way, a gas distribution method of radiating from the center to the outside is realized for the reaction gases. For the anode exhaust gas and the cathode exhaust gas as tail gases, the tail gases enter the box housing 110 from the gas distribution plate 220 along the gas distribution branch pipes 120 and are discharged along the gas distribution main pipe 130. In this way, the transfer of the tail gases from the outside to the inside is realized, which is convenient for collecting the tail gases. In this way, both the independent transmission of each intake and exhaust gas and the uniform arrangement of each gas are ensured, and the uniformity of the gas distribution of each fuel cell stack tower is ensured.

[0086] Furthermore, for a plurality of box housings 110, in one embodiment, the plurality of box housings 110 are coaxially arranged and nested inside and outside, as Figures 2 to 6 shown in the figure. It can be understood that the shapes of the plurality of box housings 110 can be the same, but the sizes are different. The outermost box housing 110 houses the second outermost box housing 110, and the second outermost box housing 110 houses the second second outermost box housing 110, and so on. Taking the outermost box housing 110 and the second outermost box housing 110 as an example, branch pipe holes can be provided on the box peripheral wall of the outermost box housing 110, and main pipe holes can be provided on the box end wall. Among them, the gas distribution branch pipes 120 and the gas distribution main pipe 130 of the second outermost box housing 110 respectively extend out along the corresponding branch pipe holes and main pipe holes, and the gaps between the gas distribution branch pipes and the branch pipe holes are sealed by welding, and the gaps between the gas distribution main pipes and the main pipe holes are sealed by welding. There are at least two box housings, that is, the box housing 110 for housing the anode gas and the box housing 110 for housing the cathode intake gas. In this way, the uniform stability of the intake gas of each fuel cell stack tower can be ensured.

[0087] Furthermore, in order to conveniently fix the second outermost box housing 110 inside the outermost box housing 110, a connecting rod can be provided between the two. For example, one end of the connecting rod is welded to the box peripheral walls of the two respectively. In this way, the two box housings 110 can be well fixed, and the stable operation of the gas distribution unit 100 is ensured.

[0088] Specifically, in order to further improve the integration of the power generation system, in one embodiment, at least the first casing 1110, the second casing 1120, the third casing 1130, and the fourth casing 1140 arranged from outside to inside are included in the multiple casings 110. The inner wall of the first casing 1110 and the outer wall of the second casing 1120 jointly surround and define a cathode tail gas chamber. The inner wall of the second casing 1120 and the outer wall of the third casing 1130 jointly surround and define a cathode intake gas chamber. The inner wall of the 1130 and the outer wall of the fourth casing 1140 jointly surround and define an anode tail gas chamber. The inner wall of the fourth casing 1140 surrounds and defines an anode fuel gas chamber, as Figures 2 to 6 shown.

[0089] A cathode tail gas branch pipe 1260 and a cathode tail gas main pipe are provided on the first casing 1110, as Figure 3 shown. A cathode intake gas branch pipe 1250 and a cathode intake gas main pipe 1330 are provided on the second casing 1120, as Figure 4 shown. An anode tail gas branch pipe 1240 and an anode tail gas main pipe 1320 are provided on the third casing 1130, as Figure 5 shown. An anode fuel gas branch pipe 1230 and an anode fuel gas main pipe 1310 are provided on the fourth casing 1140, as Figure 6 shown. Among them, the multiple casings 110 are nested in sequence from inside to outside and are separated into multiple concentrically arranged gas distribution chambers. In this way, the reaction gas and the tail gas are both integrally arranged in the gas distribution box, which is not only beneficial to improving the integration of the power generation system, but also can perform heat exchange on the reaction gas through the tail gas to improve the fuel utilization rate.

[0090] Further, in one embodiment, within the same gas distribution unit 100, the lengths of the multiple gas distribution branch pipes 120 are the same and are arranged in the same plane, as Figure 2 shown. In this way, the reaction gas can be radiated from inside to outside evenly and stably to each gas distribution plate 220; and / or, the gas distribution branch pipe 120 includes a branch pipe proximal end 1210 connected to the casing 110 and a branch pipe distal end 1220 connected to the gas distribution plate 220. The distances between adjacent branch pipe proximal ends 1210 are the same, as Figure 2 shown. It can be understood that the distances between adjacent gas distribution branch pipes 120 are equal, and the gas distribution chambers are divided into several equal parts by the gas distribution branch pipes 120. In this way, the gas in the gas distribution chamber can be evenly and stably distributed into each gas distribution branch pipe 120.

[0091] The gas distribution unit 100 further includes: a plurality of flow guiding ribs 8 vertically extending and arranged inside the casing 110 for dispersing the gas in the gas distribution chamber; and a flow guiding cover 9 located in the gas distribution main pipe 130 and covering the gas distribution main pipe 130; wherein, a plurality of flow guiding holes 10 for communicating the gas distribution main pipe 130 and the gas distribution chamber are formed on the flow guiding cover 9 at circumferentially spaced intervals, asFigure 7 and Figure 8 As shown. It can be understood that the flow guiding ribs 8, the flow guiding cover 9 and the flow guiding holes 10 can be distributed in each box housing 110, or can be distributed in some of the box housings 110. Taking the fourth box housing 1140 as an example, when the gas from the anode gas main pipe 1310 enters the fourth box housing 1140, it first enters the flow guiding cover 9 and diffuses into the gas distribution cavity through the circumferentially distributed flow guiding holes 10. In this way, the uniformity of gas distribution can be increased. The anode gas entering the gas distribution cavity increases the residence time in the gas distribution cavity through the flow guiding ribs 8, thereby improving the heat exchange efficiency with the third box housing. And the flow guiding ribs 8 contribute to the uniform distribution of the air flow, making the inlet pressures of the respective stack towers 200 of the fuel cell stack close to each other, and the outlet pressures of the respective stack towers 200 of the fuel cell stack close to each other, which helps to make the gas distribution uniform. The flow guiding ribs 8 can also enhance the structural stability of the gas distribution cavity.

[0092] Specifically, the flow guiding cover 9 can be a hemispherical member and includes a cover end face perpendicular to the axis of the gas distribution main pipe 130 and a cover circumferential face located in the circumferential direction of the axis of the gas distribution main pipe 130. The flow guiding holes 10 can be distributed on the cover circumferential face, so that the gas can be more dispersed. There are various arrangements of the flow guiding holes 10, and no specific limitation is made here. The flow guiding ribs 8 are arranged parallel to the gas distribution main pipe 130, and the number of the flow guiding ribs 8 can be calculated and adjusted according to the heat exchange requirements or the air flow pressure drop requirements, and no specific limitation is made here.

[0093] On the one hand, in order to improve the service life of the gas distribution box and ensure stable gas distribution, in one embodiment, the gas distribution box is an insulating and high-temperature resistant structural member. For example, the gas distribution box can be made of an insulating and high-temperature resistant ceramic material, or can be made of a high-temperature resistant metal material, and an alumina coating can be coated or plasma sprayed on the surface of the high-temperature resistant metal material, thereby improving the insulation and high-temperature oxidation resistance of the material surface, and avoiding the oxidation of the gas distribution box in a high-temperature environment to generate a chromium oxide layer, thus causing chromium poisoning of the fuel cell stack.

[0094] On the other hand, in one embodiment, the box housing 110 and the gas distribution plate 220 are respectively welded and fixed to the gas distribution branch pipe 120. In this way, the airtightness between the box housing 110 and the gas distribution plate 220 is ensured by welding, and the operation is simple and the connection is easy.

[0095] In the stack tower of the fuel cell stack, in one embodiment, the upper stack 210 and the lower stack 230 are both single stacks and include a plurality of battery sheets 1 stacked vertically, an upper protection plate 2 located at the top of the battery sheets 1, and a lower protection plate 3 located at the bottom of the battery sheets 1. Power-taking lugs 4 protrude from both the upper protection plate 2 and the lower protection plate 3, as Figure 15As shown in the figure. The ports of the internal gas delivery pipelines of the upper power stack 210 are on its lower protection plate 3, and the ports of the internal gas delivery pipelines of the lower power stack 230 are on its upper protection plate 2. Taking the upper power stack 210 as an example, the reaction gas enters the interior of the upper power stack 210 along the gas distribution plate 220 and the lower protection plate 3. The reaction gas undergoes a chemical reaction on the battery cells 1 to generate electricity, and power is taken through the power-taking lugs 4. In this way, the chemical energy of the reaction gas is converted into electrical energy to achieve fuel power generation.

[0096] In addition, for the gas distribution plate 220, its internal gas flow channels are designed according to the flow channels of the power stack, and the gas distribution and transmission of anode fuel gas, cathode intake gas, anode tail gas, and cathode tail gas can be achieved simultaneously. The structure of the gas distribution plate 220 can be various and is known to those of ordinary skill in the art, so no more details will be described here.

[0097] Comparatively, in existing fuel cell power generation systems, in order to achieve the series connection of single cells, connection pieces are usually used for connection. For example, the patent CN101908637B proposes a seal-less solid oxide fuel cell stack with double gas path channels. Multiple single cells are connected in series or in parallel through connection pieces. The connection method between the connection pieces and the single cells is conductive adhesive bonding, diffusion welding, or sintering. This connection method is not easy to process and is only the internal connection method of single cells, unable to achieve the external connection of the cells.

[0098] Therefore, in the fuel cell power generation system of the present invention, a power-taking connection assembly is used to connect multiple power stacks in series. In one embodiment, the fuel cell power generation system further includes a conductive power-taking connection assembly 300. The power-taking connection assembly 300 includes: a power-taking connection plate 310, which is formed with a lug accommodation groove 5 for accommodating the power-taking lugs 4; and a fixing member 320. The power-taking lugs 4 are inserted into the lug accommodation groove 5 and are electrically connected to the power-taking connection plate 310. The fixing member 320 penetrates through the power-taking connection plate 310 and the power-taking lugs 4. Among them, in the same power stack tower 200, the power-taking connection plate 310 at the top of the lower power stack 230 is connected to the power-taking connection plate 310 at the bottom of the upper power stack 210 through an inter-stack connection plate 330, so that the upper power stack 210 and the lower power stack 230 are connected in series, as Figures 7 to 14 . It can be understood that in a power stack tower, there are two types of power-taking connection assemblies 300. One is the end-position power-taking connection assembly 300 located at the vertical end of the power stack tower, such as Figure 10 , Figure 13 and Figure 14 shown. It includes a power-taking connection plate 310. The power-taking lugs 4 are inserted into the power-taking connection plate 310 and are connected and fixed through the fixing member 320. The other is the inter-stack power-taking connection assembly 300 located between the upper power stack 210 and the lower power stack 230, such as Figure 9 , Figure 11 and Figure 12As shown in the figure. It includes two power-taking connection plates 310, and each power-taking connection plate 310 is fixedly connected to the power-taking ear 4 through a fixing member 320. The two power-taking connection plates 310 are connected by an inter-stack connection plate 330. In this way, the power-taking connection plate 310 can not only form a large contact area with the power-taking ear 4, reduce resistance consumption, and increase the available power generation, but also weaken the problem of increased contact resistance caused by virtual connection due to different materials and different expansions at high temperatures, avoid stress deformation of the power-taking ear 4 at high temperatures, and protect the fuel cell stack.

[0099] Further, the fixing member 320 may include a screw and a nut. A first fixing hole may be provided on the power-taking connection plate 310, and a second fixing hole may be provided on the power-taking ear 4. The screw passes through the first fixing hole and the second fixing hole and is fixed by a nut, as Figure 9 and Figure 10 shown. It should be noted that the fixing member 320 is not limited to the above structure.

[0100] In order to realize the electric energy output of the fuel cell stack tower 200, in one embodiment, the fuel cell power generation system further includes a power-taking support rod for outputting the electric energy of the fuel cell stack tower 200. The power-taking support rod includes a power-taking upper support rod 6 and a power-taking lower support rod 7. The power-taking upper support rod 6 extends from the power-taking connection plate 310 located at the top of the upper fuel cell stack 210, and the power-taking lower support rod 7 extends from the power-taking connection plate 310 located at the bottom of the lower fuel cell stack 230, as Figure 10 shown. Through the inter-stack power-taking connection assembly 300, the upper fuel cell stack 210 and the lower fuel cell stack 230 are connected in series, and are connected to an external power-taking cable through the power-taking upper support rod 6 and the power-taking lower support rod 7 to output electric energy.

[0101] Further, in one embodiment, the inter-stack connection plate 330 and the connected power-taking connection plate 310 are an integral structural member, as Figure 11 and Figure 12 shown. As an integral structural member, it is not only convenient for processing but also can improve the structural strength. Of course, the inter-stack connection plate 330 and the power-taking connection plate 310 are not limited to being integral.

[0102] Even further, in one embodiment, the power-taking connection plate 310 is a U-shaped member and includes an ear-facing surface 3110 arranged facing the power-taking ear 4 and an ear-backing surface 3120 arranged facing away from the power-taking ear 4. The ear-facing surface 3110 surrounds and defines an ear receiving groove 5. A high-temperature conductive adhesive is provided between the power-taking ear 4 and the ear-facing surface 3110, and insulating coatings are provided on both the ear-backing surface 3120 and the inter-stack connection plate 330, as Figure 14As shown. The ear-facing surface 3110 that fits with the power-taking lug 4 is connected to the power-taking lug 4 through a high-temperature-resistant conductive adhesive, which can not only reduce the contact resistance but also serve as a protective layer to avoid the increase in resistance caused by the oxidation of the contact surface. The high-temperature-resistant conductive adhesive can be silver paste. The surface of the ear-backing surface 3120 that does not fit with the power-taking lug 4 can be an insulating coating to ensure the surface insulation of the power-taking connection assembly 300, so that it does not conduct electricity when contacting other metals. The insulating coating can be a plasma-sprayed alumina coating.

[0103] It should be specifically noted that the other components and functions of the fuel cell power generation system according to the embodiments of the present invention are known to those of ordinary skill in the art. To reduce redundancy, they will not be described in detail here.

[0104] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, such as changes in the shape, thickness, and material of the end plate sealing layer. These simple modifications all fall within the protection scope of the present invention.

[0105] In addition, it should be noted that in the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. Without contradiction, they can be combined in any suitable way. To avoid unnecessary repetition, the present invention will not describe various possible combination methods separately.

[0106] In addition, any combination can be made between various different embodiments of the present invention as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A fuel cell power generation system, characterized in that, The fuel cell power generation system includes: A gas distribution box, including a plurality of gas distribution cavities separated from each other for accommodating gases; and A plurality of stack towers (200) of fuel cell stacks, arranged around the periphery of the gas distribution box and including an upper fuel cell stack (210), a gas distribution plate (220), and a lower fuel cell stack (230) stacked vertically; At least among the plurality of gas distribution cavities, there are included an anode fuel gas cavity, an anode tail gas cavity, a cathode intake gas cavity, and a cathode tail gas cavity that are connected to the gas distribution plate (220). Among them, the plurality of gas distribution cavities are stacked vertically, and the extension line at the junction of the anode fuel gas cavity and the cathode intake gas cavity is located on the gas distribution plate (220), or the plurality of gas distribution cavities are nested inside and outside and arranged at the gas distribution plate (220), so that the plurality of upper fuel cell stacks (210) and the plurality of lower fuel cell stacks (230) can synchronously introduce and discharge gases.

2. The fuel cell power generation system according to claim 1, wherein, The gas distribution box includes a plurality of gas distribution units (100) for forming the gas distribution cavities. The gas distribution unit (100) includes: A box housing (110) that surrounds and defines the gas distribution cavity; A plurality of gas distribution branch pipes (120), one end of which is arranged at intervals on the peripheral wall surface of the box housing (110), and the other end is connected to the gas distribution plate (220); and A gas distribution main pipe (130) that extends vertically on the end surface of the box housing (110).

3. The fuel cell power generation system according to claim 2, wherein The plurality of box housings (110) are coaxially arranged and nested inside and outside.

4. The fuel cell power generation system according to claim 3, characterized in that, At least among the plurality of box housings (110), there are included a first box housing (1110), a second box housing (1120), a third box housing (1130), and a fourth box housing (1140) arranged from outside to inside. The inner wall of the fourth box housing (1140) surrounds and defines the anode fuel gas cavity, the inner wall of the third box housing (1130) and the outer wall of the fourth box housing (1140) jointly surround and define the anode tail gas cavity, the inner wall of the second box housing (1120) and the outer wall of the third box housing (1130) jointly surround and define the cathode intake gas cavity, and the inner wall of the first box housing (1110) and the outer wall of the second box housing (1120) jointly surround and define the cathode tail gas cavity.

5. The fuel cell power generation system according to claim 2, wherein Within the same gas distribution unit (100), the lengths of the plurality of gas distribution branch pipes (120) are the same and are arranged in the same plane; and / or, the gas distribution branch pipes (120) include a proximal end of the branch pipe (1210) connected to the box housing (110), and the distances between adjacent proximal ends of the branch pipes (1210) are the same.

6. The fuel cell power generation system according to claim 2, characterized in that, The gas distribution unit (100) further includes: A plurality of flow guiding ribs (8) that extend vertically inside the box housing (110) for dispersing the gas in the gas distribution cavity; and A flow guiding cover (9) located inside the gas distribution main pipe (130) and covering the gas distribution main pipe (130); Among them, a plurality of flow guiding holes (10) for communicating the gas distribution main pipe (130) and the gas distribution cavity are formed at circumferentially spaced intervals on the flow guiding cover (9).

7. The fuel cell power generation system according to claim 2, wherein The gas distribution box is an insulating and high-temperature resistant structural member.

8. The fuel cell power generation system according to claim 2, characterized in that, The box housing (110) and the gas distribution plate (220) are respectively welded and fixed to the gas distribution branch pipes (120).

9. The fuel cell power generation system according to any one of claims 1 to 8, characterized in that, The upper power cell stack (210) and the lower power cell stack (230) are both single power cell stacks and each includes a plurality of cell sheets (1) stacked vertically, an upper protection plate (2) located at the top of the cell sheets (1), and a lower protection plate (3) located at the bottom of the cell sheets (1). Power-taking lugs (4) protrude from both the upper protection plate (2) and the lower protection plate (3).

10. The fuel cell power generation system according to claim 9, wherein The fuel cell power generation system further includes a power-taking connection assembly (300) capable of conducting electricity. The power-taking connection assembly (300) includes: a power-taking connection plate (310) formed with a lug accommodation groove (5) for accommodating the power-taking lugs (4); and a fixing member (320). The power-taking lugs (4) are inserted into the lug accommodation groove (5) and electrically connected to the power-taking connection plate (310). The fixing member (320) penetrates through the power-taking connection plate (310) and the power-taking lugs (4); wherein, in the same power cell stack tower (200), the power-taking connection plate (310) at the top of the lower power cell stack (230) is connected to the power-taking connection plate (310) at the bottom of the upper power cell stack (210) through an inter-stack connection plate (330) so that the upper power cell stack (210) and the lower power cell stack (230) are connected in series.

11. The fuel cell power generation system according to claim 10, wherein The fuel cell power generation system further includes a power-taking support rod for outputting the electric energy of the power cell stack tower (200). The power-taking support rod includes a power-taking upper support rod (6) and a power-taking lower support rod (7). The power-taking upper support rod (6) protrudes from the power-taking connection plate (310) located at the top of the upper power cell stack (210), and the power-taking lower support rod (7) protrudes from the power-taking connection plate (310) located at the bottom of the lower power cell stack (230).

12. The fuel cell power generation system according to claim 10, wherein The inter-stack connection plate (330) and the connected power-taking connection plate (310) are an integral structural member.

13. The fuel cell power generation system according to claim 10, characterized in that, The power-taking connection plate (310) is a U-shaped member and includes a lug-facing surface (3110) arranged facing the power-taking lugs (4) and a lug-backing surface (3120) arranged facing away from the power-taking lugs (4). The lug-facing surface (3110) surrounds and defines the lug accommodation groove (5). A high-temperature resistant conductive adhesive is provided between the power-taking lugs (4) and the lug-facing surface (3110). Insulating coatings are provided on both the lug-backing surface (3120) and the inter-stack connection plate (330).

Images